Photographic film assemblage



Jan. 24,1961 0 A. GOVATSOS 2,969,283

PHOTOGRAPHIC FILM ASSEMBLAGE Filed April 19, 1957 2 Sheets-Sheet 1 -L lo [on .1 Suppor'l' q rPhol'osensi'l'ive Silver Halide Layer -Fluid Composii'ion 0 V K I IN VEN TOR.

ATTORNEYS United States Patent 2,969,283 PHOTGGRAPHIC FILM ASSEMBLAGE Charles A. Govatsos, West Newton, Mass., assignor to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware Filed Apr. 19, 1957, Ser. No. 653,886

7 Claims. or. 96-76) This invention relates to photography and, more particularly, to novel photographic products useful in processes wherein a fluid reagent is distributed in a layer between a pair of photographic elements for processing said elements.

A number of photographic processes have been proposed involving the spreading of a fluid reagent in a thin layer between the adjacent fluid-confining surfaces of a pair of superposed elements and allowing the sandwich thus formed to imbibe for a predetermined processing period, at the end of which the two elements are separated from one another. For example, in Patent No. 2,662,822, issued December 15, 1953, in the name of Edwin H. Land, there is described a diffusion-transfer reversal process involving the spreading of a layer of a viscous fluid reagent between an exposed silver halide emulsion layer and the surface of a print-receiving layer to effect the formation of a positive silver transfer image in the layer of fluid. At the end of a predetermined processing period the emulsion layer and print-receiving layer are stripped apart and the fluid layer in which the positive print is formed adheres to the print-receiving layer and is stripped along therewith from the emulsion ayer.

An object of the present invention is to provide a photographic product including at least a first element comprising a first fluid-confining surface adapted to be superposed with the fluid-confining surface of a second element for aiding in the spreading of a viscous fluid reagent, containing a thickening agent, in a thin layer between said fluid-confining surfaces, and so constructed as to insure the adherence of the thickened fluid layer to said first fluid-confining surface as said first element is stripped from said second element.

In the above-mentioned process the sandwich comprising the photosensitive emulsion layer, print-receiving layer and layer of fluid reagent is allowed to imbibe for a predetermined processing period which may range, for example, from 30 seconds to three minutes, and the tendency of the thickened layer of fluid to adhere to the fluid-confining surface of the print-receiving layer is a function of the length of this imbibition period. In one such process, for example, it has been found that the layer of fluid tends to adhere to the photosensitive emulsion layer at the end of an imbibtion period of one minute and is almost certain to adhere to the fluid-confining surface of the print-receiving layer at the end of a processing period of three minutes. At the end of the optimum processing period of two minutes, however, the fluid has a tendency to adhere equally to both the photosensitive and print-receiving layers, and will, as a rule, adhere entirely to the print-receiving layer when the two layers are peeled apart, if the fluid layer is adhered to the print-receiving layer in the area where peeling is commenced.

Other objects of the invention are: to provide a photographic product including an element providing at least one fluid-confining surface adapted to be peeled from ice another element, with which it is superposed, together with a thin layer of a viscous fluid spread between the fluid-confining surfaces of said elements, and including a small protuberance on its fluid-confining surface in the region thereof at which peeling apart of the elements is commenced, said protuberance being adapted to effect a reduction in the thickness of the layer of said fluid spread between said fluid-confining surfaces in said region, thereby producing the effect on the fluid in said region of materially increasing the length of the period during which the sandwich comprising the fluid-confining elements and fluid layer is allowed to imbibe; and to provide a product as described comprising a fluid reagent capable of processing a pair of superposed sheets when spread in a thin layer therebetween and of forming a film which will adhere to one of said sheets when said sheets are stripped apart following processing.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the product possessing the features, properties and the relation of components which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure l is a diagrammatic sectional view taken through a typical photographic product embodying the invention to illustrate the operation thereof, the thicknesses of the materials comprising said product being exaggerated for clarity of illustration;

Fig. 2 is a schematic perspective view of a typical product embodying the invention;

Fig. 3 is a diagrammatic plan view of the outer surface of a sheet comprising another form of product embodying the invention;

Fig. 4 is a diagrammatic plan view of the inside of the sheet of Fig.3; and

Fig. 5 is a diagrammatic enlarged plan view of a portion of Fig. 3.

The present invention is particularly concerned with products adapted to be employed in processes wherein a fluid reagent is distributed in a thin layer between an exposed photosensitive silver halide emulsion and another fluid-confining layer to effect the formation of a visible positive image by a process involving the transfer of image-forming constituents produced as a result of the development of a latent image in the silver halide emulsion. More particularly, the invention is concerned with a processand materials of the type disclosed in the aforementioned Land patent wherein the positive image is formed in the layer of fluid processing reagent which contains a thickening or film-forming agent and which is adapted to remain adhered to a second sheet comprising both a fluid-confining layer and a support for a positive print when the sheet is separated from the emulsion layer.

The invention broadly comprehends a novel product including at least a sheet adapted to function, in cooperation with another element with which it is superposed, as a fluid-confining means and as a means for supporting a film formed by a layer of fluid spread between the sheet and other element when the sheet is stripped therefrom. Products embodying the invention may also comprise the photosensitive element which includes the photosensitive silver halide emulsion layer and a rupturable container of the fluid reagent intended to be spread between the photosensitive element and the fluid-confining support sheet. The silver halide emulsion layer may be provided on any suitable support such as paper, glass and organic plastic materials and may, as suggested, comprise an 3 element of the product embodying the invention. The fluid-confining support sheet or print-receiving sheet is preferably flexible so that it can be separated from the photosensitive element by a progressive peeling action. Sheet materials suitable for this purpose are those which are usually employed as supports for photographic prints, both of the reflection and projection type, and include paper and transparent organic plastic materials suchasv cellulose acetate, cellulose nitrate and the like.

The relation of components employed in the performance of one form of the process during a stage thereof for which the product of the invention is intended-to be employed is illustrated diagrammatically in Fig. l wherein: 10 represents a photosensitive element comprising a support 10a and a photosensitive silver halide emul-' sion 10b; 12 represents a fluid-confining support sheet or print-receiving sheet adapted to aid in the spreading of a layer of fluid between sheets 10 and 12 and as a sup; port for a transfer print obtained by the process; is repre-- seats a layer of a relatively viscous fluid processing reagent; and 16 represents a mask for limiting, and sharply defining, the edges of the area in which the positive transfer print is formed.

The fluid reagent, in a preferred form, eflectuates a silver diffusion-transfer reversal process involving the development of the silver halide emulsion and the transfer of at least a portion of the silver of the unexposed regions of the emulsion to a suitable silver-receiving layer wherein the silver, upon precipitation in said silver-- developing agent such as hydroquinone, a silver halidev complexing agent such as sodium thiosulfate, adisper-v sron of solid minute particles providing silver precipitating nuclei, and a thickening agent, preferably a film-form ing colloid such as sodium carboxymethyl cellulose, capable of producing a self-supporting solid film when the liquid or solvent for the film-forming agent is removed therefrom. A fluid composition may contain other ingredients rendering the developing agent ef-.. fective to perform its function, such, for example, as an alkali and sodium thiosulfate.

Print-receiving sheet 12, in the form shown, preferably comprises a support 12a and a surface coating orimagee receiving layer 12b which may contain reagents to be dissolved in the liquid composition as it is spread and which also contains one or more-stabilizing agentsfor improving the keeping qualities of the transfer print. These stabilizing agents are contained in a suitable vehicle which can be a film of polyvinyl alcohol, methyl cellulose, sodium carboxymethyl cellulose and the like, various gums and resins, or microgranular materials.

Layer 1212 may also comprise a material applied to thesurface of support 12a to render the same more adherent to the film in which the positive image is formed. Such a layer, on a support of cellulose acetate, may comprise, for example, three subcoats, the first of which is a layer of cellulose nitrate, the second of which is a layer of a mixture of equal parts of cellulose nitrate and a hydrolyzed polyvinyl acetate which is 65 to 85% by weight polyvinyl alcohol, and the third of which comprises sodium carboxymethyl cellulose. The materials of either or both supports 10a and 12a are preferably absorbent so that they will hasten the formation of a solid imagereceiving film by absorbing the liquid or solvent for the film-forming agent from the layer of processing composition.

For further specific examples of compositions and materials useful in products and processes of the foregoing type, reference is made to the above-mentioned Patent No. 2,662,822.

The viscous fluid processing reagent is spread in a thin layer between photosensitive sheet 10 and support sheet 12 by providing a quantity of fluid between the sheets adjacent the area of the emulsion layer which is to be processed and this fluid is thereafter spread over this area by squeezing it between the photosensitive sheet and support sheet. This is accomplished, in a preferred manner, by moving the sheets in superposition between a pair of pressure-applying members. The fluid composition is initially provided for spreading between the sheets in an: elongated rupturable container18; which as shown in Fig. 2, has a length at least equal to the transverse dimension of the area over which its fluid contents are to be spread. Container 18 may be attached to one of sheets 10 and 12 and, as shown, is usually attached to the fluidconfining surface of print-receiving sheet 12. The container is formed of a rectangular blank of a sheet material, preferably one which comprises multiple layers and is impervious to air and the vapor of the processing reagent. The container is formed by folding the blank. medially and thereafter sealing together the end mar ginal portions 20 and the longitudinal marginal portions 22 of the two folded faces to provide a central cavity for containing the processing fluid. The seals at the end marginal portions 20 are stronger than the seal holding together longitudinal marginal portions 22 so that the last-mentioned seal will become unsealed in response to hydraulic pressure generated in the fluid and insure the release of the fluid in the direction of the area over which it is to be spread. Discharge of the fluid contents of the container is achieved in the same manner as is spreading of the fluid, that is, by movement of the con tainer between a pair of pressure-applying members.

One form ofphotographic product embodying the invention and shown schematically in Fig. 2 comprises. -a photosensitive sheet 10, print-receiving sheet 12;

and. container 18 of a fluid processing reagent. The? print-receiving sheet is. provided with a mask 16 in the form of; a sheet or layer attached to-the print-receiving. sheet andhaving an aperture therein defining the area ofthe print-receiving sheet in which the print can be formed. The aperture in the mask defining the printreceiving area may be of any desired shape, being rectangular in the preferred form shown, and should have at least one sharply defined corner portion the purpose of which will become apparent. The photosensitive sheet is processed following exposure of the emulsion layer by superposing the photosensitive and print-receiving sheets with the'emulsion layer and mask 16 located innermost and with container 18 located between the sheets adiaw cent one edge of the print-receiving area defined by the. aperture in mask 16. The superposed sheets are then moved, commencing in the region of container 18, be tween a pair of pressure-applying members for discharging the processing fluid from the container between the" sheets and spreading the fluid in a thin layer on the emulsion between the latter and the image-receiving surface of sheet 12; The sandwich thus formed is allowed to imbibe for a predetermined processing period ranging, for example, from one-half to three minutes, during which time an image is formed in the layer of processing fluid and said fluid layer forms a substantially solid imagereceiving film.

As previously noted, it has been discovered that the longer the imbibition period during which the sheets are maintained in superposition with the layer of fluid reagent therebetween, the greater the tendency for the layer of fluid to adhere to the print-receiving sheet. It has been found, for example, that in a process of] the type described requiring an imbibition time of two minutes for optimum results, there is considerable uncertainty as to which of the two sheets the layer of fluid will adhere when the sheets are separated and that it will almost always adhere completely to the print-receiving sheet if it is adhered thereto when and in the area wherein stripping is commenced. that the film of fluid'is almost certain to adhere to the print-receiving sheet when the imbibition period is lengthened substantially beyond two minutes, for example to It has also been discovered aeeaaea three minutes. However, this latter practice, if followed, while insuring proper stripping, would most likely have an adverse effect on the results insofar as image formation is concerned.

The present invention comprehends the construction of a film assemblage adapted to be imbibed for the optimum processing period, for examples two minutes, whereby the effect of a substantially longer processing period such as three minutes is produced in a region of the superposed sheets wherein stripping is commenced. This effect, i.e., of a longer imbibition period, is achieved by reducing the thickness of the layer of fluid reagent in this region. Since reducing the thickness of the layer of fluid may adversely affect image formation, it is important that this region or area of reduced fluid thickness be as small and hence inconspicuous as possible and at a location in the print where it is not likely to be noticed. This requirement for inconspicuousness is best met by locating the region of reduced thickness in the extreme corner of the print, and this arrangement is ideally suited insofar as the size of the region is concerned since stripping can be readily commenced in the corner from a relatively small area wherein proper adherence of the fluid film is assured.

This reduction in the thickness of the layer of fluid is obtained by providing a small protuberance or raised boss 24 on the inner or fluid-confining surface of printreceiving sheet 12. Protuberance 24 may comprise a material located on the surface of sheet 12 or, as in the preferred form of sheet 12 shown in the drawings, boss 24 is provided by embossing or dimpling the sheet just inside a corner of the print-receiving area formed by mask 16. In a typical process for which the product of the invention is intended to be employed, the fluid processing reagent is spread in a layer ranging in thickness from two to six thousandths of an inch and preferably on the order of three thousandths of an inch so that the height of the boss and hence the depth of the dimple need be only very small, that is, a fraction of the thickness of the fluid layer, and preferably on the order of one to two thousandths of an inch. The shape of the boss is not critical, preferably being generally rounded since this appears to be the most convenient. The boss need cover only a relatively small area having a diameter, for example, on the order of of an inch, so that it is inconspicuous yet sufficiently large to insure proper stripping when located as close as possible to the corner edges of the print-receiving area. Boss 24 is provided on the print-receiving sheet since the mask which defines the print-receiving area is also attached to the print-receiving sheet and it is in this manner that proper location of the boss is obtained.

The present invention may be embodied in another form of photographic product of the double roll type described in Patent No. 2,579,587, issued December 25, 1951, in the name of Edwin H. Land. This product, shown in Figs. 3-5, comprises an elongated photosensitive sheet 30 containing a plurality of exposure frames and an elongated print-receiving sheet 32 containing a plurality of print-receiving areas. The product is usually provided with the two sheets coiled in separate rolls with their leading ends joined together at a leader whereby registration can be obtained between appropriate exposure frames and print-receiving areas when the two sheets are superposed. The print-receiving sheet includes a plurality of containers 34 of a fluid processing reagent, each container being associated with a print-receiving area and mounted on sheet 32 adjacent the leading transverse edge of the printreceiving area. The two rolls are adapted to be loaded separately into a photographic apparatus wherein each frame of the photosensitive sheet is exposed and is moved in superposition with a print-receiving area of sheet 32 between 21 pair of pressure-applying members for distributing the processing reagent, carried in the container associated with the print-receiving area, in a thin layer between the associated frame and area.

Each print-receiving area, designated 36, is roughly de- 6 fined by perforations and scored or partially cut lines completely surrounding the print-receiving area. The perforations, in the form shown, extend transversely of the sheet in two lines, designated 38, located at opposite ends of the print-receiving area. The longitudinal edges of each print-receiving area are defined by pairs of partially cut or scored lines 40 extending generally parallel to the edges of the sheet and perpendicular to lines 38. The scored lines and perforations permit each print-receiving area to be separated from the photosensitive sheet and the remainder of the print-receiving sheet when processing of the exposed frame and formation of a print therefrom are complete. Stripping of the print from the photosensitive sheet as well as further handling of the print is facilitated by providing each print-receiving area with a tearout portion, designated 42. Each tear-out portion 42 is defined at its lateral edges by scored lines 46 and transversely by one of lines of perforations 38 and an angular line of perforations 44 extending transversely of the sheet substantially between score lines 40. An elongated slot 46 is provided in each tear-out portion along one longitudinal edge thereof and extending to a point closely adjacent a corner of the print-receiving area.

On that surface of the print-receiving sheet which is to be brought into superposed relation with the exposed photosensitive sheet there is preferably provided a mask 48 having therein a rectangular aperture 50 defining the edges of the portion of the print-receiving area which is to receive the positive print by the above-described process. Aperture 50 is slightly smaller than the print-receiving area defined by perforations 38 and score lines 40, thereby providing a border for the print formed in this area. Each fluid-carrying container 34 is preferably secured to the outer surface of mask 48 adjacent one edge of the printreceiving area by such means as strips of tape 52. This container, constructed as previously described, is positioned so that its contents may be discharged toward the print-receiving area for spreading across said area. For trapping excess fluid spread from the container across the print-receiving area, there is provided a fluid trap preferably comprising a pair of trapping elements 54 located adjacent the longitudinal margins of the sheet in the region of container 34. A stop hole 56 is provided in each trapping element 54 and through sheet 32 for coacting with stop elements in the apparatus in which the product is employed for predeterminedly positioning the sheets within the camera.

In the use of the product of this type, the print-receiving sheet, after being positioned in photographic apparatus such as a camera, is superposed with an exposed area of the photosensitive sheet and then moved between a pair of pressure-applying members. As the superposed sheets pass between the members, the processing fluid is forced from a container 34 and spread across the adjacent printreceiving area 36, the fluid at the edges and ends of the print-receiving area being spread between the mask and the surface of the photosensitive sheet. Any excess fluid being spread when the edge of the print-receiving area is reached is trapped between trapping elements 54 which act to separate the pressure-applying members and thus relieve the spreading pressure on the fluid. The layer of fluid spread between the photosensitive sheet and the print-receiving sheet laminates these two sheets together and concurrently effects the formation of a positive image in the layer of fluid. At the completion of this processing, the print-receiving area is stripped, together with the layer of fluid, from the photosensitive sheet. This operation is indicated best at the left-hand side of Fig. 3 where one print-receiving area is shown as being partially torn out from the remainder of the print-receiving sheet and stripped from the photosensitive sheet. Tearing of this print-receiving area is accomplished by inserting a fingernail or other suitable object into slot 46 and separating tear-out portion 42 from photosensitive sheet 30 along perforation lines 44 andscore lines 40. Continued pulling inthe direction from the lower side of the left-hand end toward the upper corner of the other end causes the print-. receiving sheet to tear along line of perforations 44 and'score lines 40 commencing in the region of one corner of the print-receiving area. It should be noted in this connection that the unperforated portions of sheet 32 separating the perforationsdn lineds'between'the tear-out portion and the print-receiving area'are sufiicientlystrong in aggregate to transmitthe tearing force from the initial tear-out portion to the longitudinalscore lines 40 to rupture these latter lines.

As previously noted; stripping orthe" print-receiving area from the photosensitive'sheet-is commencedby vir v the of the location of slot 46adjacent one edge ofthe print-receiving area at the'lower corner (viewing Fig. of the print-receivingarea. Accordingly, it is this corner of the print-receiving area wherein-stripping iscommenced and adherence between the print containingfilm; formed" by the fiuid processing reagent and the print-receiving sheet, must be assured. Accordingly, a raised boss 58 is provided in the corner of each print receiving area closest a slot 46 preferably by dimpling the print-receiving sheet. Each boss 58 is located within and closely adjacent the edges of the print-receiving area defined by aperture 50 in mask 48.

Although the print-receiving a'rea'adapted to be torn from the print-receiving sheet is shown as being rectangular in shape, other forms of print-receiving areas may be provided in accordance with the invention so long as they include at least one corner portion at which stripping or peeling is commenced, and a boss is provided in this corner within the area thereof within which the print is formed and asclose as possible to the edges thereof. The invention has been-shown and described as including'a raised boss on the'surface of a sheet which is intended to be peeled from another surface along with a film formed by a layer of fluid spread between the sheet and other surface. his to be understood, however, that the boss can be provided on either the sheet or the other surface and will function to insure adherence of the film to the other surface as well as to the surface of the sheet, depending on which of the two surfaces is constituted so as to have the greater aflinity for the fluid film. 7

Since certain changes may be made in the above product without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as'illustrative and not in a limiting sense;

What is claimed is:

1. .A photographic product comprising, in combination, a first sheet having a first substantially smooth fluid-confining surface which is treated with a fiuid processing composition distributed in contact with said surface, means coupled with said first sheet and providing a second substantially smooth fluid-confining surface, said surfaces being arranged for superposition with one another, and means containing a fluid processing composition, including a liquid medium and a film-forming agent, in sufiicient quantity to form a continuous thin layer of substantially uniform thickness between and in contact with a predetermined area of said surfaces, said area of said surfaces including a corner portion at which separation of said surfaces is commenced when processing of said first surface hy said layer of fluid is complete, said corner portion of said first surface being provided with a small protuberance having a height which is less than thethickness ofsaid layer of fluid and other dimensionswhich are ap proximately five to fiiteen times the thickness of' said layer, said protuberance being located closely adjacentthe edges of said predetermined area of said first surface and projecting toward said second surface and providingmeans for reducing the thickness of said layer of fluid spread between saidsurfaces in the region of said corner portion'eandthereby facilitatingthe adherence of a film,

formed by said-layer of 'fiuid upon removal of'said liquid medium therefrom, to one. of said surfaces" when said sheet is stripped fromsaid secondsurface'.

2. The photographic product of claim 1 wherein said first sheet comprises a section of a substantially larger sheet includingmeans defining the edges of said section andmeansfor proinoting thetearingof said section from said larger sheet commencing in the region of said corner portion; the last-mentioned means" including at least an opening in said larger; sheet near said corner portion whereby said section'canbe engagedfm simultaneously tearing it fr'om saiddarger"sheet-and peeling it from said secon'dfsu'rface:

3. Thephotographic productoficlaim 1 wherein said first fluid-confining surfaceincludes a coating of a material for 'promotingtheadherence of'said film to said first fluidconfining surface.

4. The phbtographioproduct'of claim 1 wherein said fluid includes an aqueous. liquid medium and the material comprising said firstsheet is water absorbent.

5. A photographic film assemblage for producing a visible photographic image comprising, in combination, a photosensitive? sheet including on one side a photosensitive layer of "predetermined area capable of being exposed and processed for producing a visible photographic image, a' second" sheet providing a substantially smooth fluid-confining surface at least coextensive with said predetermined area of said photosensitive layer for aiding. in the distribution of a processing fluid in a thin layer between said photosensitive layer and said surface, said sheets being joined to one another with said surface arranged for superposition with said area of said photosensitive layer, container means located between said sheets and carrying a viscous fluid processing composition including a liquid medium, a film-forming agent and an agent for reacting with said photosensitive layer, following exposure thereof, to produce a visible image, in sulhcient quantity to form a continuous thin layer of substantially uniform thickness between and in contact with said area of said photosensitive layer and said surface, said film-forming agent comprising a material for forming a substantially solid film adhering to one of said photosensitive layer and said surface upon the removal of said liquid medium fro-m said layer of fluid, and masking-means-attached to one of. said one side of said photosensitive. sheet and said surface for limiting contact be-' tween said fluid and at least one of said photosensitive layer and said surface over said predetermined area, said surface being provided with a small raised boss at a corner portion of said predetermined area projecting towardsaidphotosensitive layer, said boss having a height which is less than the thickness of said layer of fluid and other dimensions which are approximately five to fifteen times'the thickness of said layer of fluid, said boss being located closely adjacent the edges of said predetermined area and providing means for reducing the thickness of said layer of fiuid spread between said surface and said photosensitive layer in the region of said comer portion and thereby facilitating the adherence of a film, formed by said layer of fluid upon removal of said liquid medium therefrom, to said surface in the region of said boss.

when said sheets are separated from one another.

6. The photographic film assemblage of claim 5 where.- in said second sheet comprises a section of a larger sheet including means defining the edges of said section and means for promoting the tearing of said section from said larger sheet commencing in the region of said corner portion, the-last-mentioned means including at least an opening in said larger sheet near said corner portion whereby said section can beengaged for simultaneously tearing said section from said larger sheetand peeling it from said photosensitive sheet.

7. The-photographic=fihn assemblage of c-laiin where- 9 10 in said liquid medium comprises water and the material 2,612,449 Land Sept. 30, 1952 comprising at least one of said sheets is water absorbent. 2,612,452 McCune Sept. 30, 1952 2,686,717 Land Aug. 17, 1954 References Cited m the file of thls patent 2,759,825 Land Aug. 21, 1956 UNITED STATES PATENTS 5 1,470,066 Dumars Oct. 9, 1923 FOREIGN PATENTS 2,579,587 Land Dec. 25, 1951 661,392 Great Britain Nov. 21, 1951 

1. A PHOTOGRAPHIC PRODUCT COMPRISING, IN COMBINATION, A FIRST SHEET HAVING A FIRST SUBSTANTILLAY SMOOTH FLUID-CONFINING SURFACE WHICH IS TREATED WITH A FLUID PROCESSING COMPOSITION DISTRIBUTED IN CONTACT WITH SAID SURFACE, MEANS COUPLED WITH SAID FIRST SHEET AND PORVIDING A SECOND SUBSTANTIALLY SMOOTH FLUID-CONFINING SURFACE, SAID SURFACES BEING ARRANGED FOR SUPERPOSTION WITH ONE ANOTHER, AND MEANS CONTAINING A FLUID PROCESSING COMPOSITION, INCLUDING A LIQUID MEDIUM AND A FILM-FORMING AGENT, IN SUFFICIENT QUANTITY TO FORM A CONTINUOUS THIN LAYER OF SUBSTANTIALLY UNIFORM THICKNESS BETWEEN AND IN CONTACT WITH A PREDETERMINED AREA OF SAID SURFACES, SAID AREA OF SAID SURFACES INCLUDING A CORNER PORTION AT WHICH SEPARATION OF SAID SURFACES IS COMMENCED WHEN PROCESSING OF SAID FIRST SURFACE BY SAID LAYER OF FLUID IS COMPLETE, SAID CORNER PORTION OF SAID FIRST SURFACE BEING PROVIDED WITH A SMALL PROTUBERANCE HAVING A HEIGHT WHICH IS LESS THAN THE THICKNESS OF SAID LAYER OF FLUID AND OTHER DIMENSIONS WHICH ARE APPROXIMATELY FIVE TO FIFTEEN TIMES THE THICKNESS OF SAID LAYER, SAID PROTUBERANCE BEING LOCATED CLOSELY ADJACENT THE EDGES OF SAID PREDETERMINED AREA OF SAID FIRST SURFACE AND PROJECTING TOWARD SAID SECOND SURFACE AND PROVIDING MEANS FOR REDUCING THE THICKNESS OF SAID LAYER OF FLUID SPREAD BETWEEN SAID SURFACES IN THE REGION OF SAID CORNER PORTION AND THEREBY FACILITATING THE ADHERENCE OF A FILM, FORMED BY SAID LAYER OF FLUID UPON REMOVAL OF SAID LIQUID MEDIUM THEREFROM, TO ONE OF SAID SURFACES WHEN SAID SHEET IS STRIPPED FROM SAID SECOND SURFACE.
 5. A PHOTOGRAPHIC FILM ASSEMBLAGE FOR PRODUCING A VISIBLE PHOTOGRAPHIC IMAGE COMPRISING, IN COMBINATION, A PHOTOSENSITIVE SHEET INCLUDING ON ONE SIDE A PHOTOSENSITIVE LAYER OF PREDETERMINED AREA CAPABLE OF BEING EXPOSED AND PROCESSED FOR PRODUCING A VISIBLE PHOTOGRAPHIC IMAGE, A SECOND SHEET PROVIDING A SUBSTANTIALLY SMOOTH FLUID-CONFINING SURFACE AT LEAST COEXTENSIVE WITH SAID PREDETERMINED AREA OF SAID PHOTOSENSITIVE LAYER FOR AIDING IN THE DISTRIBUTION OF A PROCESSING FLUID IN A THIN LAYER BETWEEN SAID PHOTOSENSITIVE LAYER AND SAID SURFACE, SAID SHEETS BEING JOINED TO ONE ANOTHER WITH SAID SURFACE ARRANGED FOR SUPERPOSITION WITH SAID AREA OF SAID PHOTOSENSITIVE LAYER, CONTAINER MEANS LOCATED BETWEEN SAID SHEETS AND CARRYING A VISCOUS FLUID PROCESSING COMPOSITION INCLUDING A LIQUID MEDIUM, A FILM-FORMING AGENT AND AN AGENT FOR REACTING WITH SAID PHOTOSENSITIVE LAYER, FOLLOWING EXPOSURE THEREOF, TO PRODUCE A VISIBLE IMAGE, IN SUFFICIENT QUANTITY TO FORM A CONTINUOUS THIN LAYER OF SUBSTANTIALLY UNIFORM THICKNESS BETWEEN AND IN CONTACT WITH SAID AREA OF SAID PHOTOSENSITIVE LAYER AND SAID SURFACE , SAID FILM-FORMING AGENT COMPRISING A MATERIAL FOR FORMING A SUBSTANTIALLY SOLID FILM ADHERING TO ONE OF SAID PHOTOSENSITIVE LAYER AND SAID SURFACE UPON THE REMOVAL OF SAID LIQUID MEDIUM FROM SAID LAYER OF FLUID, AND MASKING MEANS ATTACHED TO ONE OF SAID ONE SIDE OF SAID PHOTOSENSITIVE SHEET AND SAID SURFACE FOR LIMITING CONTACT BETWEEN SAID FLUID AND AT LEAST ONE OF SAID PHOTOSENSITIVE LAYER AND SAID SURFACE OVER SAID PREDETERMINED AREA, SAID SURFACE BEING PROVIDED WITH A SMALL RAISED BOSS AT A CORNER PORTION OF SAID PREDETERMINED AREA PROJECTING TOWARD SAID PHOTOSENSITIVE LAYER, SAID BOSS HAVING A HEIGHT WHICH IS LESS THAN THE THICKNESS OF SAID LAYER OF FLUID AND OTHER DIMENSIONS WHICH ARE APPROXIMATELY FIVE TO FIFTEEN TIMES THE THICKNESS OF SAID LAYER OF FLUID, SAID BOSS BEING LOCATED CLOSELY ADJACENT THE EDGES OF SAID PREDETERMINED AREA AND PROVIDING MEANS FOR REDUCING THE THICKNESS OF SAID LAYER OF FLUID SPREAD BETWEEN SAID SURFACE AND SAID PHOTOSENSITIVE LAYER IN THE REGION OF SAID CORNER PORTION AND THEREBY FACILITATING THE ADHERENCE OF A FILM, FORMED BY SAID LAYER OF FLUID UPON REMOVAL OF SAID LIQUID MEDIUM THEREFROM, TO SAID SURFACE IN THE REGION OF SAID BOSS WHEN SAID SHEETS ARE SEPARATED FROM ONE ANOTHER. 